Elapsed time - how many whole hours pass

A math lesson for 2nd grade. We use a time line or an "hour line" to figure out how many hours it is from one given time to another. When one of the times is AM and the other PM, we need to figure the elapsed time in two parts. We also solve some word problems involving clock and time. The first one has to do with starting time, when elapsed time and ending time are known. The second one asks how many hours Mathy - my mascot mammoth - slept during the night, when his sleep was broken up into several sections.